Fabric conditioning compositions, in particular fabric softening compositions to be used in the rinse cycle of laundry washing processes, are well known. Typically, such compositions contain a water-insoluble quaternary-ammonium fabric softening agent, the most commonly used having been di-long alkyl chain ammonium chloride.
The anti-harshening effect of cellulase on fabrics is known from e.g. FR 2 481 712 or GB-A-1 368 599, as well as their fabric care benefits, disclosed in e.g. EPA 269 168, all incorporated herein by reference in their entirety. Cellulases have been mainly described however for use in detergent compositions to be used in the main wash cycle of laundry processes, and have found some commercial application in this context.
In spite of such teachings, the use of cellulases in rinse added fabric softener compositions has apparently not been commercially pursued so far. The reason may be that one of the potential issues to be resolved is to provide acceptable stability of the cellulase in such compositions upon storage. Another reason may be potential issues to be resolved around the effectiveness of cellulase use in the rinse cycle following a normal detergent wash cycle. Such conditions are typically of shorter duration and lower temperatures than used in the wash cycle, and there are concerns around potential for fabric damage if too high activity cellulase conditions are met by the rinse cycle use conditions and/or by carry over of cellulase activity from use of cellulase-containing detergents in the wash cycle.
It has been discovered that rinse added fabric softener compositions can be formulated to contain cellulase to provide cellulase activity during normal use conditions to be within certain limits so as to provide fabric softening benefits with an acceptable impact on fabric wear. The present invention therefore allows to formulate fabric softening compositions over the entire typical pH range of fabric softening agents, including pH of 5 to 7 for traditional fabric softening actives, while achieving both effectiveness and fabric safety benefits.